摘要:
A semiconductor memory device includes a memory core unit including a memory cell array including a plurality of memory cells and a sense amplifier to sense and amplify data of the plurality of memory cells, and a self refresh control unit to apply at least one first core voltage to the memory core unit and to control a self refresh operation to be performed at every first self refresh cycle, in a first self refresh mode, and to apply at least one second core voltage to the memory core unit and to control the self refresh operation to be performed at every second self refresh cycle, in a second self refresh mode. In the semiconductor memory, a level of the at least one first core voltage is higher than that of a corresponding one of the at least one second core voltage, and the first self refresh cycle is shorter than the second self refresh cycle.
摘要:
A probe sensing pad used to detect a position of a probe needle includes a probe area, at least two sensing regions contacting peripheral portions of the probe area, sensing elements of different electrical characteristics connected to corresponding sensing regions, and at least one isolation region for electrically insulting the sensing regions. The position of the probe needle relative to the probe sensing pad may be rapidly detected and automatically corrected toward a desired contact site of the probe sensing pad depending upon the voltage measured by a probe needle contacting the probe sensing pad. That is, the measured voltage will have a first value if deflected in a first direction, a second value (different from the first) if deflected in a second direction, and so on. The position of the probe needle can be corrected based on this measurement.